Spawn Larva

The Queen injects 3 (4 in WoL and HotS) Larva eggs into a Hatchery which after 29 seconds (40 in WoL and HotS), hatch and 3 Larvae are ready to be used at the targeted Hatchery. Up to 19 Larvae per Hatchery can be spawned. If a Hatchery has 3 or more Larvae, it will not naturally create more.

Contents

Spawn Larva is the most powerful ability at the Queen's disposal. At every possible chance, the Queen's energy should be used to spawn additional Larva at a particular Hatchery. One Queen will recover enough energy to constantly spawn Larva at one Hatchery. This ability increases the ability of Zerg to produce any type of unit, so the Zerg no longer have to get multiple Hatcheries. As a general rule of thumb, each base the Zerg obtains can support one Hatchery with a Queen and its Spawn Larva ability.

When opening with Zerglings it is especially important to be using Spawn Larva at every available opportunity. The low cost of Zerglings and Drones means Larvae are used up very quickly. Missing even a single Spawn Larva while building primarily Zerglings and Drones can result in a stiff halt in production.

This spell can also be used on allied Hatcheries. For example, on team maps with close starting positions, one zerg can pursue Lair tech right after the Spawning Pool, while his team mate transfers a Queen (after casting spawn larva on her "home") over. This is usually followed by a Vespene donation as soon as e.g. Mutalisks become available.

Allows you to monitor the progress of injects easily because you can go through the control groups to see how far the injection is from completion, therefore it's easier not to miss injects even when your hatcheries are not synchronized

Having each Hatchery on its own hotkey has various advantages such as being able to easily produce units at a Hatchery that's getting attacked for shorter reinforcement paths or setting separate rally points for Hatcheries

Cons:

Takes a long time.

Takes up many control groups.

Tip:
You should still use an extra control group for all your Hatcheries for easier production.